GitHub Open-Sources Internal Load-Balancing Software

GitHub will release as open source the GitHub Load Balancer (GLB), its internally developed load balancer.

GLB was originally built to accommodate GitHub’s need to serve billions of HTTP, Git, and SSH connections daily. Now the company will release components of GLB via open source, and it will share design details.

“Historically one of the more complex components has been our load-balancing tier,” said Joe Williams, GitHub senior infrastructure engineer, and Theo Julienne, GitHub infrastructure engineering manager, in a co-authored bulletin. “Traditionally we scaled this vertically, running a small set of very large machines running haproxy and using a very specific hardware configuration allowing dedicated 10G link failover.”